1. Field of the Invention
The present invention relates to an apparatus for and method of printing. More particularly, the present invention relates to an apparatus for and method of printing a mono-color image in a single-pass color printer.
2. Description of the Related Art
An electrophotographic printer prints an image through processes of an exposure, a development, a transfer, a fusing, and a cleaning. Referring to FIG. 1, light corresponding to image information is irradiated onto a photosensitive drum 1 using an exposing unit 2 (exposure) to form an electrostatic latent image. The developer 3 supplies toner to the electrostatic latent image to form a toner image (development). The toner image is transferred and fused onto a sheet of paper (P) directly or through an intermediate transfer belt 4 to print the image. After performing the transfer process, a blade 5 of FIG. 1 is installed to be in contact with the photosensitive drum 1 in order to remove waste toner remaining on the photosensitive drum 1. The blade 5 is generally formed of a rubber material having elasticity such as urethane.
A single-pass color printer generally includes four photosensitive drums 1, four exposing units 2 for forming the electrostatic latent images on the four photosensitive drums 1, and four developers 3 for supplying toners of black (K), cyan (C), magenta (M), and yellow (Y) colors to the electrostatic latent images formed on the photosensitive drums 1 to develop the images. The four photosensitive drums 1 contact the intermediate transfer belt 4. The toner images of K, C, M, and Y colors formed on the four photosensitive drums 1 are transferred onto the intermediate transfer belt 4 while overlapping with each other to form a color toner image. When the color toner image is transferred and fused onto the paper, the full-color image is printed on the paper.
The single-pass color printer can also print a mono-color image. In a case where the mono-color image is printed, the toner image is developed on one photosensitive drum 1 only. However, the photosensitive drums that are not engaged with the image forming operation should be rotated since these contact the intermediate transfer belt 4.
There is a problem in the prior art in that the waste toner functions as a lubricant between the photosensitive drum 1 and the blade 5. However, since the toner image is not developed on the photosensitive drums 1 that are not engaged with the image forming operation, the waste toner is rarely generated. Therefore, the photosensitive drums 1 that are not related to the image forming operation may be damaged by the friction between the photosensitive drum 1 and the blade 5. In addition, the blade 5 may be bent as shown in FIG. 1 by the dotted line.